Macbook won't restart

[Alejandra36]

I have a Macbook pro running on Mavericks.
The problema is that won't restart. It gets stuck on a grey screen with a Wheel runing for hours until I have to turn it off with the power button.
Anyone know the solution?
Thanks!

 

[satcomer]

Boot into Recover mode and try to repair OS X or disk.

 

[skillets]

If you use Avid products you might try removing



/Library/Audio/Plug-Ins/HAL/Avid CoreAudio.plugin/

or

/Library/Audio/Plug-Ins/HAL/Digidesign CoreAudio.plugin/



this was the cause of three of our computers not shutting down after the El Capitain upgrade. After removing the first shutdown will require "sudo shutdown -r now" from the terminal or press and hold the power button. This solved the problem for all three computers for us.